- Thousands of firefighters were struggling on August 2 to contain two vast wildfires in California, one of which has become one of the most destructive blazes in the state's history.
The National Park Service said Yosemite Valley is not threatened by the fire as of Friday at noon.
The 11-day-old Carr Fire, which has scorched almost 127,000 acres (54,000 hectares) in the scenic Shasta-Trinity region north of Sacramento, remains the largest and most fearsome of 18 significant wildfires burning across California and more than 100 nationwide.
Fanned by erratic winds in fuel-choked, tinder-dry forests and scrub, the California blazes have torched 468,467 acres (189,580 hectares) so far this year, destroyed 1,823 homes and structures, and killed at least eight people.
"I expect to see that Ranch Fire continue to grow, and just surpass on its own the Carr Fire", said McLean.
The weather service issued warnings for critical fire weather conditions into Saturday, saying a series of dry low-pressure systems passing through the region would bring afternoon wind gusts.
"This is a particularly risky situation with extremely low humidity and high winds". It has destroyed 88 structures and forced the evacuation of 14,000 residents, including in the towns of Nice and Lucerne about 93 miles (150 km) north of San Francisco, according to the California Department of Forestry and Fire Protection (CalFire).
Over 4,300 personnel assigned to the blaze have carved containment lines around 37 percent of the perimeter of the blaze.
A fire whirl - similar to a tornado - that occurred in the Carr Fire near Redding on July 26 had maximum winds in excess of 143 miles per hour, according to an initial analysis by the National Weather Service and Calfire.
Dykema said the whirl uprooted trees and tore roofs from home. Most are in other western states but wildfires have also struck Texas and Florida, according to the National Interagency Fire Center.
He says fire whirls are common, but not at the intensity recorded on July 26.
As of Saturday morning, Cal Fire reported The Ranch Fire was 156,678 acres and 27-percent contained.
Workers who live in Yosemite's popular Valley region were ordered to leave Friday because of inaccessible roads.
The report says the death of the 10-year veteran highlights the need for better risk assessment, communication and supervision.
The Carr Fire in northern California has burned more than 130,000 acres in a two-week span, killing six people, displacing 35,000, and destroying more than 1,500 buildings.